Painting On Chocolate Mmf: Will Paint Show?

I was inspired by a halloween themed cake that was recently posted on CC It has a dark blue sky with silohuettes on it. I really like the effect and want to paint my cake with blues/dark blues. Since I'm making a chocolate cake, I want to cover it in Chocolate MMF but am not sure if it will be too dark. I don't want to end up with a brown cake that I can't paint blue.

Has anyone painted on Chocolate MMF before; do the colors show? Or should I just make regular MMF